Twenty Five Years of Ozone Soundings at NOAA
NOAA record includes longer term time series (~25 years) and mid length series (10-15 years)
� All of the soundings have been done with electrochemical concentration cell (ECC) ozonesondes.
� Over the course of the record there have been a number of changes in methodology.� Analog chart data recording vs. digital sondes, VIZ vs. Vaisala
radiosondes, box vs. pump temperature (applies to time series > 20 years in length).
� Shorter time series (<20 years) used digital sondes, Vaisalaradiosondes, measured pump temperature.
� Ozonesondes from different manufacturers and with different sensing solution recipes were used.
� The background current was inconsistently measured and different pump efficiency corrections were applied.
How can these potential inhomogenities be accounted for?
� Use results of the JOSIE chamber experiments (Herman’s talk).
� Make use of laboratory experiments to measure the impact of sensor solution recipes and measure pump efficiency corrections.
� Use the results of dual soundings to develop corrections.
� Examine the methodology and conditions under which background currents were measured at various locations and during different observational periods (e.g., humid vs. dry conditions, analog vs. digital eras).
How can we use the results from JOSIE to improve the NOAA ozonesonde record?
Conclusion: The ENSCI-Z sondes produce a stronger response
to ozone than the SPC-A sondes.
How can we use the results from JOSIE to improve the NOAA ozonesonde record?
SST-1: 1% KI, full buffer; SST-2: 0.5% KI, half buffer; SST-3: 2% KI, no buffer
Conclusion: The buffered solutions produce a stronger response
to ozone that increases with altitude in the stratosphere.
How can we improve the NOAA ozonesonde record?Role of sensing solution recipe and pump correction
Conclusion: (1) The response of the sensor is only weakly a function of the
potassium iodide concentration but strongly influenced by the solution buffer. (2) Smaller pump efficiency correction compensates for the influenceof the buffer in the upper portion of the profile.
How can we improve the NOAA ozonesonde record?Role of background current
Conclusion: When mixing ratios are low (tropics) upper tropospheric ozone
can be impacted by using inappropriate background currents. In some cases,especially with older data, this is significant.
Small Measured Background Avg. Measured Background Large Measured Background
How can we improve the NOAA ozonesonde record?Use of dual soundings
Conclusion: Correcting for the buffer gives good agreement between the profiles.
Also correcting for the sonde type (6A) improves the comparison for total ozone.
Suva, Fiji29April 1998
Suva, Fiji29April 1998
Total OzoneTOMS-EP 254 DU1%, buff. 262 DU2%, unbuff. 245 DU
Total OzoneTOMS-EP 254 DU1%, buff. 254 DU2%, unbuff. 251 DU
Uncorrected Corrected
How can we improve the NOAA ozonesonde record?Use of dual soundings
Conclusion: Correcting for the buffer gives good agreement between the profiles.
Boulder, CO29 January 1998
Total OzoneDobson 300 DU1%, buff. 333 DU2%, unbuff. 303 DU
Uncorrected Corrected
Boulder, CO29 January 1998
Total OzoneDobson 300 DU1%, buff. 310 DU2%, unbuff. 303 DU
How can we improve the NOAA ozonesonde record?Use of dual soundings
Conclusion: Correcting for the buffer gives good agreement between the profiles.
Total OzoneDobson 1%, buff. 144 DU2%, unbuff. 130 DU
Uncorrected Corrected
South Pole11 October 2003
Total OzoneDobson 1%, buff. 139 DU2%, unbuff. 130 DU
South Pole11 October 2003
How can we improve the NOAA ozonesonde record?Use of dual soundings
Conclusion: The weakly buffered (1/10) 1% KI solution performs very similarly to
the 2% KI, unbuffered solution.
Total OzoneOMI 322 DU 1%, 1/10 buff. 333 DU2%, unbuff. 328 DU
Uncorrected Uncorrected
Boulder, CO 30 August 2006
Total OzoneDobson 285 DU 1%, 1/10 buff. 297 DU2%, unbuff. 296 DU
Trinidad Head, CA20 December 2004
How can we improve the NOAA ozonesonde record?Use of dual soundings
Uncorrected
Boulder, CO 17June 2009
Total OzoneDobson 298 DU 1%, 1/10 buff. 310 DU1%, 1/10 buff. 310 DU
What does this mean for producing a longer term time series?
� Unlike many measurement systems that are based on a single instrument measuring over a relatively long period, each ozonesonde profile is from a different instrument.
� Consistent procedures are very important in a system like the ozonesondes but it is possible (maybe even likely) to do things consistently incorrectly (e.g. treatment of the background current).
� An independent total column ozone measurement for comparison with the integrated ozonesonde profile is a useful way of checking the stability of the system.
Comparison of Hilo Corrected Ozonesonde and Mauna Loa Umkehr Time Series (8 – 16 hPa)
Comparison of Corrected Ozonesonde and Umkehr Time Series (16 – 32 hPa)
Comparison of Corrected Ozonesonde and Umkehr Time Series (32 - 63 hPa)
Comparison of Corrected Ozonesonde and Umkehr Time Series (63 - 125 hPa)
Comparison of Corrected Ozonesonde and Umkehr Time Series (125 hPa - Surface)
Conclusion:
Longer Term NOAA Sonde Records
Records of more than 20 years:
� Boulder: 1967-1971, 1979 - present
� Hilo: 1982 – present
� South Pole: 1968-1971, 1986 – present
� Samoa: 1986-1990, 1995 – present
Records of more than 10 years
� Trinidad Head, California
� Huntsville, Alabama
� Fiji
� Galapagos
Conclusions
� Varying equipement (Z vs. A sondes), sensing solution recipes, and background treatment have introduced inhomogenities in the NOAA ozonesonde record.
� Use of the results of the JOSIE Chamber experiment, other laboratory tests, and dual soundings provide useful information for developing correction procedures.
� Application of this information seems to produce a more homogeneous time series, but does not remove all suspected discrepancies
� Comparison with other profile time series show broad consistency but more detailed comparison is warranted.
SHADOZ Contributions
to Vertical Trend StudiesSHADOZ in its 14th Year!
– > 5000 profile sets at <http://croc.gsfc.nasa.gov/shadoz>
– GCOS Affiiliate (2007), NDACC “Cooperative Network” (2009)
– SHADOZ DVD ! Website Images & Data
Recent Examples of Trends & UT/LS Ozone
SHADOZ Activities to Enhance Value– Added Hilo, Hanoi Sites since 2008
– Maintain coverage – current efforts to restore Irene, Ascension, San Cristobal
– V5 re-processing in 2011 to list background current, pump flow (see Vömel & Diaz, 2010)
– Continual participation in WMO/JOSIE type activities.
** Review: Thompson, Oltmans, Tarasick, Smit, von der Gathen, Witte: Atmos. Environ., D-10-0009, in press.
Operational, 2008-2010
WHO is SHADOZ: Co-I’s in <http://croc.gsfc.nasa.gov/shadoz>
Thompson et al, JGR, 108, 8238, doi: 10.1029/2001JD000967, 2003
Right: SHADOZ Sites, 1998-2010
Participants Affiliation Country
Anne M Thompson – PI ator NASA/GSFC, Penn State USA
Jacquie Witte - Archiver SSAI, NASA-GSFC USA
Rene Stuebi, G Levrat MeteoSwiss Switz.
K K Chow (partners – H
Tsuruta/S Yonemura, JP)
Malaysian Met. Service Malaysia
Gert J R Coetzee, K Motolo So. African Wea Service S. Africa
Masatomo Fujiwara Hokkaido University Japan
Rinus Scheele KNMI Nether.
Kenyan Meteor. Dept. Kenya
N P Leme Brazil Space Agency Brazil
Gi Laneve (thru 2006) Rome University Italy
Vietnam Met Service Vietnam
S J Oltmans, B Johnson NOAA/GMD USA
Françoise Posny La Réunion University France
Frank J Schmidlin NASA/WFF USA
Masato Shiotani, T Ogina Kyoto University Japan
N Komala, S Sasripriya Indonesian Space
Agency (LAPAN)
Indo-
nesia
Valérie Thouret (2006-2007) CNRS France
2009-11 Milestones, Activities* Added Hilo Data Archive from
NOAA/GMD
* Hanoi joined (M Shiotani, Kyoto U)
* WMO Data Managers Toronto
meeting recommends more Level 0
data. SHADOZ to add Background
Current info
* Remedying data gaps:Fiji (NOAA-GMD, B Johnson)
Ascension (NASA, F Schmidlin)
Irene (So Afr Weather, G Coetzee)
Example of ENSO Effect on Ozone Variability at
SHADOZ Sites (Left), Trends & Series of Models
from CCMVAL2 Activity (Right)
From Randel & Thompson,
JGR, in press
Gravity Wave (GW) frequency, mean %, 15-20 km (Left),(Left),
from Laminar Method, maximum at convective season,
site, eg Kuala Lumpur. GW Index shows ENSO Link (Right)(Right)
ENSOENSO
Thompson et al., JGR, in press
Example of On-going Evaluations
• SHADOZ-OMI (TOMS version, thru
2009) shows improved agreement
relative to SHADOZ-TOMS (1998-
2004) discrepancy in total ozone
(Left)
• Offsets of mean profiles for
individual SHADOZ stations suggest
high bias over Paramaribo (Right)
New OMI (TOMS v8 Algorithm) – SHADOZ Total Ozone
Comparisons, 2005-2009
Problem with integrated total in archive
OMI (TOMS v8 Algo.) – SHADOZ Comparisons, 2005-2009
Sonde
Type
Change?
Acknowledgments, References
• Aura Validation & SHADOZ (M J Kurylo, K W Jucks, NASA); NDACC (M Kurylo, G Braathen); WMO (L Barrie, G Braathen) & JOSIE (H G J Smit)
• SHADOZ Co-Is & National Sponsors
• SHADOZ DVD – Oct 2010!
• References– T Deshler et al., balloon experiment to test ECC-ozonesondes from different
manufacturers, and with different cathode solution strengths: Results of the BESOS flight, J. Geophys. Res., 113, D04307, doi:10.1029/2007JD008975, 2008.
– H G J Smit et al, Assessment of the performance of ECC-ozonesondes under quasi-flight conditions in the environmental simulation chamber: Results from the JuelichOzonesonde Intercomparion Experiment chamber (JOSIE), J. Geophys. Res., 112, D19603, doi: 10.1029/2006JD007308, 2007.
– W J Randel and A M Thompson, Interannual variability and trends in tropical ozone
derived from SHADOZ ozonesondes and SAGE II satellite data, J. Geophys. Res., 2010JD015195, in press.
– A M Thompson et al., Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998-2004 tropical ozone climatology. 3. Instrumentation, station variability, evaluation with simulated flight profiles, J. Geophys. Res., 112, D03304, doi: 10.1029/2005JD007042, 2007.
– A M Thompson et al., Gravity and Rossby wave signatures in the tropical troposphere and lower stratosphere based on Southern Hemisphere Additional Ozonesondes(SHADOZ), 1998-2007, J. Geophys. Res., doi: 10.1029/2009JD013429, in press, 2011.
– A M Thompson et al., Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998-2009 tropical ozone climatology. 4., in prep, 2011